1. Field
The following description relates to a method and system for estimating a location of a mobile device, and more particularly, to a method and system for estimating a location of a mobile device located in means of transportation through WiFi and a method of updating a database used in the location estimation.
2. Description of the Related Art
Recently, a variety of location-based services (LBS) are provided. The LBS is a service which makes business more productive and makes life more convenient based on location information. As smart phones are widely released to the public, the LBS is increasingly popular.
In association with a geographic information system (GIS), the LBS is widely used in a variety of industrial applications, such as transportation, distribution or disaster management. The LBS may be used in public transportation arrival announcement, navigation, chauffeur call, taxi call, and quick delivery. The LBS also includes find-pals services, stop station announcement services, shopping district advertising services, augmented reality services and social network services.
For the LBS, it is essential to easily and accurately acquire location information. In order to acquire location information, global positioning system (GPS) satellites or base stations for cellular phones have typically been used. While the GPS satellites are widely used to easily and accurately acquire location information, they exhibit serious weaknesses in some applications.
For example, in order to find a location of a mobile device located in a subway train, base stations for cellular phones are currently used for location estimation since GPS satellite signals fail to reach underground regions. For buses or trains running on the ground, the chances are high that mobile devices located in the buses or trains fail to receive GPS satellite signals due to their roofs. Besides, it takes a high operation performance and a long time to calculate location information using the GPS satellite signals. While base stations for cellular phones are used for such applications, this method exhibits a very low accuracy in location estimation.
Methods of easily and accurately acquiring location information of mobile devices located in such means of transportation as buses, subways, trains, ships and aircrafts have not been proposed. Besides, it is difficult to find a location of a mobile device located in means of transportation in motion. For such means of transportation as a ship or an aircraft which moves out of the coverage area of a base station for cellular phones, the method of using base station signals for cellular phones cannot be used in acquiring location information.